Vegetarian nutrition may contribute for metabolic differences that we proposed to explore non-invasively. 6 omnivores and 6 lacto-ovo-vegetarians underwent a 7T MRI exam including proton and phosphorus magnetic resonance spectroscopy to measure creatine (tCr), phosphocreatine (PCr) and triglyceride components in the soleus muscle. tCr and unsaturated fatty acids concentration were reduced in vegetarians but similar PCr/γ-ATP ratios were found. We show that vegetarian diet induces lower skeletal muscle creatine and different lipid profiles, which was not associated with altered bioenergetic reserve. This protocol opens new avenues to explore the impact of diet in skeletal muscle.